The present invention is directed toward an electronic caliper and more particularly, toward a caliper which may be programmed and used as an electronic measuring device for measuring distances on surfaces, such as images and maps, and displaying the actual distances in correct units (by previously entering a scale factor).
There are many types of measuring instruments currently known and used in science and industry for measuring precise but relatively small dimensions. These known instruments include, for example, rulers, micrometers, calipers, and microscopes, depending upon what is being measured and the accuracy required. In general, these known instruments include a scale which is read by a person after the instrument has been manipulated. Some problems encountered with the use of such instruments, however, are human error and difficulty in reading the scale or translating dimensions.
One scientific field in which accurate measurements are vital is medicine. Physicians, for example, currently use pocket protractors in order to determine actual dimensions of an X-ray image. Images are measured utilizing the protractor and the measurement must then be adjusted or scaled to the scale indicated on the X-ray. A dimension can then be calculated. This is, however, a somewhat tedious and inaccurate method for translating the dimensions of an X-ray to the exact dimensions of the anatomy being depicted thereon.
Another example of a measuring device is described in U.S. Pat. No. 4,229,883 to Kobashi. This patent discloses a measuring instrument which includes a digital display. The instrument includes a caliper body with measuring jaws that are moveable toward and away from each other. The measured dimensions may be seen in a digital display. While this patent seeks to eliminate human error in reading the scale, it is still rather large and cumbersome and may be unsuitable when smaller measurements must be taken, for example, from an X-ray.
U.S. Pat. No. 4,566,199 to Gruhler et al. discloses a sliding caliper with measuring beaks and a digital display. While this device and others like it may have advantages over prior manual devices, they are normally too large for a physician to easily carry in his or her pocket. Furthermore, they are not very versatile in that they have use only as a caliper and normally still require that the reading taken be scaled in order to obtain an accurate measurement.
The present invention is designed to overcome the deficiencies of the prior art discussed above. It is an object of the present invention to provide a caliper which may be programmed and used as an electronic measuring device.
It is another object of the present invention to provide a caliper which is versatile and easy to use.
It is an even further object of the present invention to provide a caliper which includes a writing utensil integral therewith so that the user can immediately record the measurement taken by the device.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a caliper which includes an elongated body with measuring means located on one end of the device including a member that slidable out of and into the main body of the device. Located on the body is a digital display that displays a distance proportional to the distance that the sliding member is slid out of the body. Within the main body are appropriate electronics and a power source. A number of buttons on the outside of the body are used to program the device and to introduce a scale factor. A writing implement such as a pen or the like is attached to the opposite end of the device for ease in recording the measurement taken by the device.
Other objects, features, and advantages of the invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings.